Tag: Aviation and Aeronautics

UTEP to Boost Training of Next-Gen Engineers with $5.3M Grant

Newswise — EL PASO, Texas (Aug. 21, 2023) – The University of Texas at El Paso is scaling up its role in preparing the next generation of engineers for U.S. aerospace and defense manufacturing sectors. The effort is supported by a new $5,300,000 grant from the Air Force Research Laboratory (AFRL).

The funds will enhance a variety of training programs offered by the UTEP Aerospace Center’s Digital Engineering Aerospace and Defense Systems Design Centers (DEDCs) in El Paso; Youngstown, Ohio; and Huntsville, Alabama. The new funds are a follow-up investment to a fiscal year 2021 grant from the AFRL that supported the creation of the DEDCs.

“UTEP stands among the top 5% of research universities in the United States,” said Ahmad Itani, Ph.D., UTEP vice president for research. “That fact, along with the growing stature of our engineering expertise and instructional capabilities, make our University uniquely well-suited for the critical task of preparing the workforce that will ensure our country remains competitive in a world where design and engineering processes of systems of all kinds evolve at an unprecedented rate.”

Digital engineering entails the use of computing and software instruments to expedite and enhance various phases of engineering, including system design, production, testing, evaluation, adaptation and upkeep. This method holds the potential to accelerate design, reduce expenditures and facilitate collaboration. It can also substantially decrease the costs associated with long-term system maintenance.

“Digital engineering will allow America to keep and increase its technological advantage,” said Ahsan Choudhuri, Ph.D., UTEP associate vice president for the Aerospace Center and the grant’s principal investigator. “That is why innovation in digital engineering and talent development with advanced digital skills are crucial. This grant represents a substantial vote of confidence from AFRL in our ability to carry out this important task.”

The project will leverage the expertise of the UTEP Aerospace Center’s DEDCs. Using an immersive learning approach, it will provide pre-professional experiences to 200 engineering and technology students. Undergraduate and graduate students from various universities, as well as students from two-year colleges and Career and Technical Education (CTE) programs in grades 9 through 12, will be recruited for the program.

Many of these students will have the opportunity to work as interns and undergraduate and graduate research assistants at the DEDCs for a 12-month program.

In addition to student development, the DEDCs will offer a course in the principles of digital engineering. Approximately 100 participants from federal agencies, aerospace and defense contractors and small and medium manufacturers will have the opportunity to enhance their knowledge in this field.

To learn more about the UTEP Aerospace Center and the Digital Engineering Aerospace and Defense Systems Design Centers, visit www.utep.edu/aerospace/Design%20Centers/index.html.

About The University of Texas at El Paso

The University of Texas at El Paso is America’s leading Hispanic-serving University. Located at the westernmost tip of Texas, where three states and two countries converge along the Rio Grande, 84% of our 24,000 students are Hispanic, and half are the first in their families to go to college. UTEP offers 169 bachelor’s, master’s, and doctoral degree programs at the only open-access, top-tier research university in America.

University of Texas at El Paso

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August 18, 2023
Possible? Climate-neutral air travel

Newswise — Researchers at the Paul Scherrer Institute PSI and ETH Zurich have performed calculations to work out how air traffic could become climate-neutral by 2050. They conclude that simply replacing fossil aviation fuel with sustainable synthetic fuels will not be enough. Air traffic would also have to be reduced. The researchers are publishing their results today in the journal Nature Communications.

The European Union aims to be climate neutral by 2050, a target that was set by the European Parliament in 2021. Switzerland is pursuing the same goal. The aviation sector, which is responsible for 3.5 percent of global warming, is expected to contribute its fair share – especially since the greenhouse gas emissions of aircraft are two to three times higher per passenger or freight kilometre than in other transport sectors. The International Civil Aviation Organisation (ICAO) and many airlines have therefore announced their intention to reduce CO₂ emissions to zero by 2050 or to become climate neutral.

In a new study, researchers at PSI and ETH Zurich have now calculated whether this can be achieved, and how. “An important question is what exactly we mean by zero carbon or climate neutrality,” says Romain Sacchi of PSI’s Laboratory for Energy Systems Analysis, one of the study’s two lead authors. If this is only referring to the CO₂emitted by aircraft actually in the air, adds his co-author Viola Becattini from ETH Zurich, this does not go nearly far enough. Because assuming that air traffic continues to grow as it has in the past, the calculations predict that the CO₂emissions of aircraft will only account for about 20 percent of their total climate impact by 2050. In order to make aviation as a whole climate neutral, it is necessary to ensure that not only flying but also the production of fuel and the entire aviation infrastructure have no further impact on the climate.

However, the study concludes that this cannot be achieved by 2050 using the climate measures that are currently being pursued in flight operations. “New engines, climate-friendly fuels and filtering CO₂ out of the atmosphere in order to store it underground (carbon capture and storage, or CCS) will not get us there on their own,” says Marco Mazzotti, Professor of Process Engineering at ETH. “On top of this, we need to reduce air traffic.”

Non-CO₂ effects play a major role

In their study, Sacchi and Becattini looked at various different scenarios. These showed, on the one hand, that while the climate impact of the infrastructure, i.e. manufacturing aircraft and building and operating airports, does need to be taken into account, it is comparatively small overall for the period up until 2050 and beyond. The impact of flying itself on the climate, and of the emissions from producing the fuel are far greater. That in itself was nothing new.

What had been less clear before was the importance of so-called non-CO₂ effects, which occur in addition to CO₂ emissions. The bulk of the greenhouse effect caused by aviation is not due to the carbon released into the atmosphere by burning aviation fuel, but to the particulate matter (soot) and nitrogen oxides that are also released and that react in the air to form methane and ozone, water vapour and the condensation trails that lead to the formation of cirrus clouds in the upper atmosphere. “Many analyses and ‘net zero’ pledges so far have ignored these factors,” says Romain Sacchi. “Or they have not been calculated correctly.”

It is customary to express emissions and effects like these in terms of CO₂ equivalents when calculating the overall balance. “But the methods and values used to date have proved to be inappropriate,” says Marco Mazzotti. “We therefore adopted a more precise approach.” The methods they used take into account one major difference between the various factors: non-CO₂ effects are much more short-lived than CO₂, which is why they are also called “short-lived climate forcers”, or SLCFs for short. While about half of the emitted carbon dioxide is absorbed by forests and oceans, the other half remains in the air for thousands of years, dispersing and acting as a greenhouse gas. Methane, on the other hand, has a much greater impact on the climate, but decomposes within a few years; contrails and the resulting clouds dissipate within hours. “The problem is that we are producing more and more SLCFs as air traffic increases, so these are adding up instead of disappearing quickly. As a result, they exert their enormous greenhouse impact over longer periods of time,” says Viola Becattini. It’s like a bathtub with both the drain and the tap open: as long as the tap lets in more water than can escape through the drain, the bathtub will keep getting fuller – until eventually it overflows.

Climate-friendly fuel alone does not achieve the goal – but it helps

“But this analogy also demonstrates that the crucial lever is under our control: the volume of air traffic,” Romain Sacchi points out. “By flying less instead of more often, in other words closing the tap instead of opening it, we can actually cool the atmosphere and push the greenhouse effect caused by aviation towards zero.” This is not to say that we must stop flying altogether. The calculations performed in the study show that for aviation to achieve climate neutrality by 2050, air traffic will need to be reduced by 0.8 percent every year – in conjunction with underground carbon dioxide storage – if we continue to use fossil fuels. This would bring it down to about 80 percent of today’s volume by 2050. If we manage to switch to more climate-friendly fuels based on electricity from renewables, 0.4 percent per year will be sufficient.

The study also took a closer look at these new fuels. Researchers around the world are working to replace conventional petroleum-based engines. As in road transport, this could be achieved by using electric batteries, fuel cells or the direct combustion of hydrogen. However, the available energy density is only sufficient for small aircraft on short routes, or in the case of hydrogen also for medium-size planes on medium-haul flights. Yet large aircraft on long-haul flights of more than 4000 kilometres account for the majority of global air traffic and greenhouse gas emissions from aviation.

Synthetic aviation fuel has pros and cons

In addition, propulsion technologies for the aviation industry based on electricity or hydrogen are far from being ready for a widespread roll-out. So-called Sustainable Aviation Fuel (SAF) is therefore viewed as the industry’s great hope. This man-made aviation fuel could replace petroleum-based aviation fuel more or less one-to-one, without the need to redesign turbines and aircraft.

SAF can be produced from CO₂ and water via a production cascade. The CO₂ is extracted from the air using a process known as air capture, and hydrogen can be obtained from water by electrolysis. “If the necessary processes are carried out entirely using renewable energy, SAF is virtually climate-neutral,” says Christian Bauer from the PSI Laboratory for Energy Systems Analysis, who was involved in the study. “This makes us less dependent on fossil fuels.” Another advantage of SAF is that it produces fewer SLCFs, which would have to be offset by capturing equivalent amounts of CO₂ from the air and storing them underground. This is significant because CO₂ storage capacity is limited and not reserved exclusively for the aviation industry.

Air tickets three times more expensive

SAF also has certain disadvantages though, in that it takes far more energy to produce than conventional aviation fuel. This is mainly because producing hydrogen via electrolysis takes a lot of electricity. In addition, energy is lost at every step in the production process – air capture, electrolysis and synthesisation. Using large amounts of electrical power, in turn, means expending more resources such as water and land. SAF is also expensive: not just in terms of the electrical power required, but also the cost of carbon capture and electrolysis plants, which makes it four to seven times more expensive than conventional aviation fuel. In other words, the widespread use of SAF makes carbon-neutral aviation a possibility, but it also costs more resources and more money. This means that flying will have to become even more expensive than it already needs to be in order to meet the climate targets. “Anyone buying a ticket today can pay a few extra euros to make their flight supposedly carbon neutral, by investing this money in climate protection,” says Romain Sacchi. “But this is greenwashing, because many of these measures for offsetting carbon are ineffective. To fully offset the actual climate impact, tickets would have to cost about three times as much as they do today.”

“Such a hefty price hike should significantly reduce the demand for flights and bring us closer to the goal of climate neutrality,” says Viola Becattini. In addition, SAF production is expected to become cheaper and more efficient over the years as quantities increases, and this will have a positive effect on the carbon footprint. The study took such dynamics into account – including the fact that the electricity mix used to produce SAF is shifting. This distinguishes the analysis from most others.

“The bottom line is that there is no magic bullet for achieving climate neutrality in aviation by 2050,” says Sacchi. “We cannot continue as before. But if we develop the infrastructure for storing CO₂ underground and producing SAF quickly and efficiently, while also reducing our demand for air travel, we could succeed.”

Paul Scherrer Institute

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July 7, 2023
Air taxi future jeopardized by urban buildings

Newswise — The air taxi market is almost ready for take off, with companies such as Boeing, Hyundai, Airbus and Toyota building fleets to have commuters flitting through the sky. Europe and the US have both drafted new rules to pave the way for air taxis to begin operations within the decade, with Australia’s Civil Aviation Safety Authority (CASA) to follow suit.

Increasingly sophisticated studies over recent years, including a recent paper by RMIT University’s Uncrewed Aircraft Systems (UAS) Research Team, have measured how sudden wind gusts form around city buildings and destabilise aircraft.

Lead researcher and aerospace engineer, Dr Abdulghani Mohamed, who’s studied wind gust dynamics for over a decade, says this aspect needs to be adequately addressed by regulation in Australia and overseas before we fill our city skies with air taxis and other drones.

Strong wind gusts form around city buildings

Low-flying aircraft are at risk from wind gusts because they land and take off at low speed, explained Mohamed, with the RMIT research revealing sudden wind gusts can pose significant safety challenges for air taxis and drones in under a second.

As a result, air taxis and drones will need more power for landing or taking off in cities compared with an airport or an open space, he explained.

“These aircraft need powerful motors that can rapidly change the thrust generated by the propellers to rapidly force the vehicle back on-course, a process which requires more energy,” said Mohamed, from the School of Engineering.

Making our city skies safe

Regulations for Advanced Air Mobility (AAM) aircraft, such as future air taxis, are being compiled around the world, including the US and Europe. The RMIT team emphasises that weather frameworks are needed to ensure this new technology is safe and reliable.

“Regulations and certification need to specifically address safe operation when traversing building flow fields,” Mohamed said.

He argues that site-specific wind simulations and measurements are essential to identify hazardous regions.

“As we determine the location of vertiports – where these vehicles will take off and land – we also need to determine hazardous regions to avoid. This will enhance safety and reduce interruption of a fleet due to wind conditions,” Mohamed said.

“In Australia, it is not clear yet whether this falls under CASA’s jurisdiction or the Bureau of Meteorology, however, air taxis will need to be provided with weather information at much higher resolution and faster rates than currently possible. This is important for flight planning.

“The margin of error will be much lower than at airports, where large aircraft can tolerate much stronger gusts. We won’t have that flexibility with air taxis in cities.”

Next steps

“Purpose-built vertiports mean we could integrate geometric design features to reduce hazardous flow conditions from occurring, and we are exploring this in our current research,” Mohamed said.

“Existing buildings can also be repurposed as vertiports but may require modifications to improve the aerodynamics near the landing pads. The effectiveness of such design features can be assessed through either scaled experiments in wind tunnels or through full-scale measurements.

“Extensive wind flow mapping at full-scale will no longer be daunting in the future. We are continuing to develop our wind sensing drones – a swarm of drones instrumented with wind anemometers – to very accurately map around large infrastructure.”

‘Gusts Encountered by Flying Vehicles in Proximity to Buildings’ is published in MDPI’s Drones (DOI: 10.3390/drones7010022). The recommendations could help shape the regulation of vertiports, flight paths and air taxi requirements in Australia and potentially globally.

The researchers are continuing research into wind gusts around buildings, with further exploration of different building shapes that may minimise adverse effects. They are also continuing to study the sensitivity of vehicles to gusts and turbulence, as well as flight-stability technologies.

This research was conducted in collaboration with the University of Maryland and Lehigh University, and was funded by the US Airforce Office for Scientific Research and DSI Group.

RMIT University

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June 23, 2023
How aircraft can fly through smoke-filled skies

Navigating smoke-filled skies may seem like a new challenge to those in the Eastern United States, but aerospace researchers have long been preparing aircraft to fly under just such conditions. Professor Jeffrey Bons of The Ohio State University is an expert in the field of particulate deposition, the study of dust/sand/salt/pollutant build up on aircraft engines. His laboratory is internationally renowned for maximizing the efficiency of gas turbine engines operating in particulate-filled atmospheric conditions, like those occurring downwind of wildfires. While not typical of the skies above most of the U.S., similar conditions are commonly encountered in flights over deserts, active volcanoes and highly polluted areas. Professor Bons can discuss advanced technology used in gas turbine jet engines to mitigate the risks of airborne particulate build up, including decreased performance and engine failure.

Ohio State University

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June 9, 2023
Propellers are louder over ground, researchers find

BYLINE: Laura Thomas

Newswise — The effects of the ground on propeller noise have been measured experimentally for the very first time by researchers in the Aeroacoustics research team at the University of Bristol.

In findings, published in the Journal of Sound and Vibration, the team found clear differences in the noise characteristics of propellers when over ground, known as ‘Ground Effect’, compared to when operated normally. They noted an overall noise increase when measuring at angles above the ground, with hydrodynamic and acoustic interaction effects being a key factor to the overall noise trends.

It is hoped this research, tested in the National Aeroacoustic Wind Tunnel facility, can inform strategies to reduce the noise of aircraft while taking off or landing, by either changing the design of the landing pads or by changing the design of proposed aircraft architectures.

Lead author Liam Hanson explained: “In light of the need for greener aviation, there has been a push in the aviation industry to develop electrified aircraft.

“There is a lot of potential benefits from electric aircraft which have been identified by a variety of companies worldwide, including all of the major aircraft manufacturers.”

However, if urban air services such as on demand air taxis are to become a reality within city limits, engineers must tackle the issue of sound pollution, generated by propellers.

An important subset of electric aircraft being developed recently are for the purposes of Advanced Air Mobility (AAM). These aircraft can be broadly considered to fit in three different categories.

The first is Electric Vertical Take-Off and Landing (eVTOL) aircraft which is focussing on Urban Air Mobility (UAM) applications such as air taxis, patient transfers, rooftop-to-rooftop trips within cities and airport transfers.

The second category is Electric Conventional Take-Off and Landing (eCTOL) aircraft which is being developed for Regional Air Mobility (RAM). RAM focusses on cargo deliveries, short-range flights and passenger transfers from rural regions.

The most commonly recognisable electric aircraft, small Unmanned Aircraft Systems (sUAS) or drones, can be considered the third category which focusses on videography, small package delivery and medical supply transfer.

Each of these categories of electric aircraft often uses propellers or rotors to generate thrust to take off and land. Crucially, eVTOL aircraft are operating in urban areas with large populations and as a result the noise generated by the aircraft is critical to understand and reduce if UAM is to be possible.

The propellers used by the aircraft are smaller than helicopters which have been in use for years, usually being far smaller in diameter and rotating at higher speeds. As a result the noise characteristics are very different to the existing knowledge, and so further research is required.

While eVTOL and sUAS aircraft are taking off or landing from a rooftop or landing pad, the propellers are likely to experience Ground Effect, an aerodynamic phenomenon which changes the performance of propellers.

This change in the propeller aerodynamics within Ground Effect changes the acoustic performance of the propellers and causes complex interactions.

Liam said: “Until now, no literature existed for the problem of isolated propeller noise in ground effect.

“Our research sought to answer for the first time what happens to propeller noise while it operates in Ground Effect and what are the key acoustic and aerodynamic interactions which are most important to understand.

“For the first time we have comprehensively measured the noise of small-scale propellers during take-off and landing while interacting with the ground. It is clear we can expect louder eVTOL aircraft during take-off and landing if the complex interactions with the ground are not considered.”

Based off their new understanding of propeller noise in Ground Effect, they are now conducting additional tests on different methods to potentially reduce the noise of the entire system.

The research was sponsored by Embraer S.A. and the Horizon 2020 SilentProp project (agreement number 882842).

Paper:

‘Experimental investigation of propeller noise in ground effect’ by Liam Hanson et al in Journal of Sound and Vibration.

University of Bristol

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May 23, 2023
Researchers create high-temp, extreme environment sensors

Newswise — Extreme environments in several critical industries – aerospace, energy, transportation and defense – require sensors to measure and monitor numerous factors under harsh conditions to ensure human safety and integrity of mechanical systems.

In the petrochemical industry, for example, pipeline pressures must be monitored at climates ranging from hot desert heat to near arctic cold. Various nuclear reactors operate at a range of 300-1000 degrees Celsius, while deep geothermal wells hold temperatures up to 600 degrees Celsius.

Now a team of University of Houston researchers has developed a new sensor that was proven to work in temperatures as high as 900 degrees Celsius or 1,650 degrees Fahrenheit, which is the temperature mafic volcanic lava, the hottest type of lava on Earth, erupts.

“Highly sensitive, reliable and durable sensors that can tolerate such extreme environments are necessary for the efficiency, maintenance and integrity of these applications,” said Jae-Hyun Ryou, associate professor of mechanical engineering at UH and corresponding author of a study published in the journal Advanced Functional Materials.

The article, which was featured on the cover of the journal, is titled “Piezoelectric Sensors Operating at Very High Temperatures and in Extreme Environments Made of Flexible Ultrawide-Bandgap Single-Crystalline AlN Thin Films.”

Making It Work

The UH research team previously developed III-N piezoelectric pressure sensor using single-crystalline Gallium Nitride, or GaN thin films for harsh-environment applications. However, the sensitivity of the sensor decreases at temperatures higher than 350 degrees Celsius, which is higher than those of conventional transducers made of lead zirconate titanate (PZT), but only marginally.

The team believed the decrease in sensitivity was due to the bandgap – the minimum energy required to excite an electron and supply electrical conductivity – not being wide enough. To test the hypothesis, they developed a sensor with aluminum nitride or AlN.

“The hypothesis was proven by the sensor operating at about 1000 degrees Celsius, which is the highest operation temperature among the piezoelectric sensors,” said Nam-In Kim, first author of the article and a post-doctoral student working with the Ryou group.

While both AlN and GaN have unique and excellent properties that are suitable for use in sensors for extreme environments, the researchers were excited to find that AlN offered a wider bandgap and an even higher temperature range. However, the team had to deal with technical challenges involving the synthesis and fabrication of the high-quality, flexible thin film AlN.

“I have always been interested in making devices using different materials, and I love to characterize various materials. Working in the Ryou group, especially on piezoelectric devices and III-N materials, I was able to use the knowledge I learned in my studies,” said Kim, who earned his Ph.D. in materials science and engineering from UH in 2022. His award-winning dissertation was on flexible piezoelectric sensors for personal health care and extreme environments.

“It was very interesting to see the process leading to the actual results and we solved the technical challenges during the development and demonstration of the sensor,” he added.

What’s Next?

Now that the researchers have successfully demonstrated the potential of the high-temperature piezoelectric sensors with AlN, they will test it further in real-world harsh conditions.

“Our plan is to use the sensor in several harsh scenarios. For example, in nuclear plants for neutron exposure and hydrogen storage to test under high pressure,” Ryou said. “AlN sensors can operate in neutron-exposed atmospheres and at very high-pressure ranges thanks to its stable material properties.”

The flexibility of the sensor offers additional advantages that will make it useful for future applications in the form of wearable sensors in personal health care monitoring products and for use in precise-sensing soft robotics.

The researchers look forward to their sensor being commercially viable at some point in the future. “It’s hard to put a specific date on when that might be, but I think it’s our job as engineers to make it happen as soon as possible,” Kim said.

University of Houston

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May 19, 2023
Prepare for Landing: Making Airports More Efficient

Newswise — WASHINGTON, March 28, 2023 – Air traffic is a significant and complex problem. Near misses between passenger planes on runways have been making headlines lately and raising safety concerns as airports try to accommodate more travelers in the wake of COVID-19. Also, as any disgruntled air traveler knows, a single aircraft’s late arrival at a busy airport can trigger an avalanche effect and cause a series of subsequent delays.

In Chaos, from AIP Publishing, a team of scientists from Spain and Argentina presented an original oscillating short-term memory model, with just two parameters, to study the dynamics of landing events at 10 major European airports. The model can estimate how landing volumes will influence those in consecutive hours – a critical ability given airport capacity constraints and external events that cause landing delays.

Altogether, the model demonstrates that statistical analyses of hourly plane landing volumes can yield valuable insights into airport operations.

“Characterizing chains of landing delay events, especially quantifying the temporal scale, is key for evaluating an airport’s operational performance,” said author Felipe Olivares. “If directly identifying interactions is not possible, a solution is to analyze the signatures they leave in time series as representative of the system’s aggregated dynamics. The main idea [of the study] is to use statistical physics tools to obtain insights about airport operations when only macroscale information, the hourly landing volume, is available.”

One of the model’s parameters represents the correlation between consecutive hours in landing volume as a metric of an airport’s landing operations efficiency.

“This could also help assess the evolution of a facility’s efficiency, understood as the capacity of handling a given traffic volume while generating minimal interaction between aircraft,” said Olivares.

The study also examined the differences between dynamics before and after the peak of COVID-19, determining that the landing flow became more random post-pandemic. That means consecutive hours in landing flow were less correlated. But this was not only caused by reduced traffic because of travel restrictions: it also might reflect a change in interactions between aircraft.

A first of its kind, the study showcases how, via statistical physics, macroscale aeronautical data analysis can reveal information on microscale dynamics.

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The article “Markov-modulated model for landing flow dynamics: An ordinal analysis validation” is authored by F. Olivares, L. Zunino, and M. Zanin. It will appear in Chaos on March 28, 2023 (DOI: 10.1063/5.0134848). After that date, it can be accessed at http://aip.scitation.org/doi/full/10.1063/5.0134848.

ABOUT THE JOURNAL

Chaos is devoted to increasing the understanding of nonlinear phenomena in all areas of science and engineering and describing their manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See https://aip.scitation.org/journal/cha.

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American Institute of Physics (AIP)

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March 28, 2023
Aerospace engineering student Amber Porteous named Brooke Owens Fellow

BYLINE: Russ Nelson

Newswise — Amber Porteous, an aerospace engineering senior from Mobile, Ala., slated to graduate in May, has been selected to receive the Brooke Owens Fellowship. The student is the second Brooke Owens Fellow from The University of Alabama in Huntsville (UAH), a part of the University of Alabama System, in the past two years, joining 2022 Fellow Megan Jordan.

“Amber is a great example of what I believe a student should be,” says Dr. Richard Tantaris, a clinical assistant professor in the MAE department and faculty advisor for the Space Hardware Club (SHC). “She is very smart, hardworking and able to handle huge responsibilities such as Space Hardware Club president. She has a great personality and has demonstrated her desire and ability to help people, bring new ideas forward and learn about the aerospace industry.”

The fellowship class of 2023 includes 47 Fellows selected from nearly 1,000 applicants worldwide. Each Fellow is matched with an aerospace internship, as well as an executive-level mentor who will support and work with them to help launch their careers.

The Brooke Owens Fellowship was founded in 2016 to honor the memory of industry pioneer and pilot D. Brooke Owens, who passed away in 2016. The program celebrates its ongoing mission and legacy of disrupting the historical gender imbalance in the aerospace industry by continuing its mission to provide opportunities and access to talented young professionals from women and gender minorities from all backgrounds.

Porteous will be interning with Lonestar Lunar, a startup company in St. Petersburg, Fla., that plans to send data centers to the Moon. “They are looking to send up a payload later on this year,” she notes. “That’s what I will be working on this summer.”

The UAH senior is the current president of the SHC and has been active with the Two-Month Glider Challenge, both the CanSat and Tartarus projects, and acted as the Outreach Manager for the club to share aerospace engineering knowledge with K-12 students. As the Project Lead, she also helped to establish an amateur ham radio contact with the International Space Station.

“CanSat is an international mock satellite competition,” Porteous notes. “I worked on the mechanical subteam to make parachutes, early payload prototypes and fiberglass shell manufacturing, and my team placed 5th in the competition. Tartarus is the SHC liquid bi-propellant rocketry team, and I learned the basics of LabVIEW through the project.”

The senior is currently on the CROSSGUARD team as well, which focuses on composite manufacturing and documentation for the SHC. She presides over a group of 260 student members across all projects, helping them to gain hands-on experience designing and building aerospace hardware.

“I wanted to take on this role, because I have a lot of passion for aerospace and mentoring,” she explains. “SHC has been a big part of my college experience in becoming more confident in myself as a leader and engineer.”

As to her future, Porteous says she would like to work with composite structures or satellite systems. “I would also like to become a STEM teacher after having a career in engineering,” she says. “Or start up a non-profit that focuses on bringing STEM education to communities where K-12 students may not have as many opportunities in the field.”

University of Alabama Huntsville

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February 24, 2023
Comparing airfares instead of seat size fairer indicator of passenger carbon emissions

Newswise — Allocating passenger aircraft emissions using airfares rather than travel class would give a more accurate idea of individual contributions, finds a study led by UCL.

Emissions calculators base their estimates on travel class, assuming that someone travelling in a higher class and therefore taking up more space on the plane is responsible for more emissions.

The study, published in Environmental Research Letters, describes how including airfares in calculations shows which passengers contribute the most revenue to the airline operating the aircraft, thereby allowing the plane to fly.

Although in general, premium (business) seats are more expensive than economy, the researchers found when looking at data that many late bookings in economy class, often made for business trips or by high income travellers, cost as much as, or more than, premium seats.

Lead author Dr Stijn van Ewijk (UCL Civil, Environmental & Geomatic Engineering) said: “The paper shows we should follow the money when calculating emissions of individual travellers, as it is revenue that decides whether an airline can operate a plane or not. Someone who has paid twice as much as a fellow traveller contributes twice as much to the revenue of the airline and should be allocated twice the emissions. The seat size of each travel class, which is currently used to allocate emissions, is only a rough approximation of how much passengers pay.”

The researchers say that using airfares to calculate passenger emissions would benefit efforts to address climate change by encouraging people on all budgets to find alternative modes of transport where possible. It would also increase estimates of corporate emissions because it allocates more to expensive late bookings, which are often made for business purposes.

Implementing a tax that is proportionate to the price of the ticket could make the total costs of flying fairer. People buying the most expensive tickets would pay the highest tax, encouraging them to seek alternatives.

Whilst taxes differ between countries, typically the rates are the same across each travel class. Travellers buying expensive tickets, who are more likely to have higher incomes, pay a relatively low tax and are not currently discouraged from flying.

Dr Van Ewijk added: “An equitable approach to reducing airline emissions should not just deter travellers who can only afford the cheapest early bookings but also the big spenders who bankroll the airline. By assigning emissions based on ticket prices, and taxing those emissions, we can make sure everyone pays their fair share, and is equally encouraged to look for alternatives.”

A ticket tax should also take into account the distance flown and the model and age of plane, which can indicate how polluting it is.

The authors used a dataset from the USA to test their fare-based allocation approach. They used the Airline Origin Survey database, which includes ticket fare data, origin and destination, travel class and fare per mile. From this, they calculated the distribution of ticket prices across all passengers on a typical flight.

Based on the price distribution, the authors allocated emissions to passengers, and compared the results with estimates from widely used emissions calculators. Since ticket prices vary strongly by time of booking, the emissions per passenger varied too, far more than on the basis of seat size and travel class.

Using an economic supply–demand model, the researchers estimated how a carbon tax on emissions would affect travellers, depending on whether the emissions the tax applied to were calculated from seat size and travel class, or the airfare. In all scenarios, a tax on emissions calculated from airfares had a more equitable effect because it reduced flying more evenly across income groups.

The researchers hope to effect policy change in calculating and taxing passenger emissions, to ensure travellers on all budgets are encouraged to seek other forms of transport where possible or consider how essential the journey is.

Notes to Editors

Stijn van Ewijk, Shitiz Chaudhary, Peter Berrill; Estimating passenger emissions from airfares supports equitable climate action will be published in Environmental Research Letters on Wednesday 25^th January, 12:00 UK time, 07:00 ET and is under a strict embargo until this time.

The DOI for this paper will be 10.1088/1748-9326/acaa48

Additional material

Graphs and figures from the paper

Credit: Dr Stijn Van Ewijk

University College London

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January 25, 2023
Model analysis of atmospheric observations reveals methane leakage in North China

1. Background

Natural gas is a relatively clean burning fossil fuel, that causes less air pollution than coal and is widely used in the world. Recent studies have shown that the natural gas leaks from production, supply chain, and end-use facilities are a large source of atmospheric methane (CH₄), and the leaking budget is underestimated in many places by bottom-up inventories. CH₄ is the second most important greenhouse gas (GHG) contributing to global warming after carbon dioxide (CO₂), with a relatively shorter lifetime, making the reduction of CH₄ emission a suitable target for implementing rapid and achievable mitigation strategies of the Paris Agreement.

Over the last decade, natural gas has become the fastest-growing fossil energy source in China due to the coal-to-gas government initiative that has been implemented to reduce air pollution and CO₂ emissions. Natural gas consumption has increased dramatically from 108.5 billion standard cubic meters (bcm) (4% of primary energy consumption) in 2010 to a record level of 280 bcm (7.6% of primary energy consumption) in 2018. In addition, according to China’s energy plan, the share of primary energy from gas will keep increasing and is likely to reach 15% by 2030, while coal and oil consumption will decline. From 2010 to 2018, the length of gas supply pipelines in urban areas of China increased approximately three-fold from 298 to 842 thousand kilometers. However, CH₄ leakage from those pipelines has not been actively reported, and there is limited publicly available data on upstream emissions and local distribution of natural gas emissions in China.

2. Research Outline and Results

In this study, we used nine years (2010–2018) of CH₄ observations by the Greenhouse gases Observing SATellite “IBUKI” (GOSAT) and surface station data from the World Data Centre for Greenhouse Gases (WDCGG) to estimate CH₄ emissions in different regions of China. GOSAT observes the column-averaged dry-air mole fractions of CH₄ in the atmosphere, and the surface stations monitor CH₄ concentrations near surface. The observation data were used for simulations by the high-resolution inverse model NTFVAR (NIES-TM-FLEXPART-variational) to infer the surface flux of CH₄ emissions. Inverse modelling optimizes prior flux estimates, which are constrained so that an acceptable agreement between the simulated and observed atmospheric concentrations is achieved.

Figure 1 shows the model-estimated CH₄ fluxes in four regions of China. The four regions, North China (NE), South China (SE), North-west China (NW), and the Qinghai-Tibetan Plateau (TP), vary with respect climate, geographical features, types of agriculture, major economic activities, and CH₄ emission sources. The model-estimated average CH₄ emissions from the four subregions over the period 2010–2018 are 30.0±1.0 (average ± standard deviation) Tg CH₄ yr^-1 from the SE region, 23.3±2.7 Tg CH₄ yr^-1 from the NE region, 2.9±0.2 Tg CH₄ yr^-1 from the NW region, and 1.7±0.1 Tg CH₄ yr^-1 from the TP region. The trends in CH₄ emissions have varied in the different regions of China over the last nine years, with significant increase trends detected in the NE region and the whole China.

We focused our analysis on the NE region where natural gas production and consumption have increased dramatically and are likely one of the main contributors to the increase estimated in regional total CH₄ emissions. The CH₄ emissions from natural gas, including leakage from fuel extraction, processing, transport, and the end-use stage, were estimated using an approach that combined data for the province-level emissions inventory and published inverse model studies. The model-estimated total CH₄ emissions and the estimated natural gas emissions both increased significantly during 2010–2018 (Figure 2). The total amount of natural gas emissions due to leakages constitutes a significant waste of energy and value. For example, in 2018, natural gas consumption in the NE region was 101.5 bcm and the estimated total natural gas emissions were 3.2%–5.3% of regional consumption.

Figure 3 shows the changes in estimated CH₄ emissions from natural gas and the model-estimated total CH₄ emissions for 2010-2018 compared to previous years in the NE region. The year-over-year change in the model-estimated total CH₄ emission closely follows the changes in CH₄ emissions from natural gas. In January 2016, record cold wave hit the region causing a sudden increase in natural gas use, and natural gas suppliers recorded an increase in natural gas loss (i.e., the difference between the amount of gas purchased and the amount of gas sold). Simultaneously, the atmospheric observations also captured the emission changes, as reflected in our inverse estimates (Figure 3). The analysis shows a strong correlation between trends in natural gas use and the increase in the atmospheric CH₄concentration over the NE region, which is indicative the ability of GOSAT to monitor variations in regional anthropogenic sources.

3. Future Perspectives

The findings of our study highlight that the increase in natural gas use threatens China’s carbon reduction efforts. The increase in CH₄ leaks from natural gas production and the supply chain will adversely affect the interests of diverse stakeholders, despite the introduction of carbon reduction measures. Given that the large natural gas distribution pipelines span more than 900 thousand kilometers in China, natural gas leaks constitute a significant waste of energy and value. The year-over-year changes in regional emissions and trends were detected by satellite and surface observations in this study. In the future, additional observations using high-resolution satellites will help to more accurately quantify emissions and provide scientific directions for emission reduction measures. There is also a need to further detect and locate such leaks using advanced mobile platforms in order to effectively mitigate CH₄ emissions in China and bring about economic, environmental, and health benefits.

4. Data Availability

GOSAT data used in this study are available from the GOSAT Data Archive Service https://data2.gosat.nies.go.jp/index_en.html

In-situ methane observation data are archived on the WDCGG Global Network: https://gaw.kishou.go.jp/

Emissions Database for Global Atmospheric Research (EDGAR) emission inventories are available for download at

https://edgar.jrc.ec.europa.eu/

Global Fire Assimilation System (GFAS) fire emissions Database are from https://www.ecmwf.int/en/forecasts/dataset/global-fire-assimilation-system

Wetland emission by Vegetation Integrative SImulator for Trace gases (VISIT) model are available at

https://www.nies.go.jp/doi/10.17595/20210521.001-e.html

The NIES airborne and Japan-Russia Siberian Tall Tower Inland Observation network (JR STATION) data are available at

https://db.cger.nies.go.jp/ged/en/index.html

The Japanese 55-year Reanalysis (JRA-55) data from the Japanese Meteorological Agency (JMA) are available at

https://search.diasjp.net/en/dataset/JRA55

5. Supplementary Information

○ Greenhouse gases Observing SATellite “IBUKI” (GOSAT)

The Greenhouse Gases Observing Satellite “IBUKI” (GOSAT) is the world’s first spacecraft to monitor the concentrations of the two major GHGs CO₂ and CH₄ from space. NIES has promoted the GOSAT series projects for GHG observation from space, together with the Ministry of the Environment, Japan (MOE) and the Japan Aerospace Exploration Agency (JAXA). GOSAT (IBUKI) is the first satellite in the series and has been observing column-averaged concentrations of CO₂ and CH₄ for more than 13 years since its launch in 2009. The second satellite, GOSAT-2 (IBUKI-2) was launched in 2018 and started observing carbon monoxide in addition to CO₂ and CH₄. Furthermore, the third satellite, Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW) is under development and due for launch in Japanese fiscal year 2023.

○ Lifetime of methane in the atmosphere

Methane is the second most important well-mixed GHG contributing to human-induced climate change after CO₂. The lifetime of CH₄ in the atmosphere refers to the time that CH₄ stays in the air after being emitted from a variety of sources. CH₄ is removed from the atmosphere mostly by chemical reactions. The atmospheric lifetime of CH₄ is 10 ± 2 years, which is relatively shorter than that of CO₂ (approximately 5 to 200 years) (IPCC, 2013).

○ Methane emission sources

Methane is emitted from a variety of anthropogenic and natural sources. Approximately 60% of all CH₄ emissions come from anthropogenic sources, such as agricultural activities, waste treatment, oil and natural gas systems, coal mining, stationary and mobile combustion, and certain industrial processes. Natural emissions include wetlands, freshwater bodies such as lakes and rivers, and geological sources such as terrestrial and marine seeps and volcanoes. Other smaller sources include ruminant wild animals, termites, hydrates and permafrost.

○ Underestimation of methane emissions from oil and gas using bottom-up inventories

Methane can leak into the atmosphere from upstream/downstream natural gas operations (i.e., extraction and gathering, processing, transmission and storage, and distribution) and end-use combustion. Atmospheric measurement studies have shown that a large amount of CH₄ emissions from oil and gas production are unaccounted for in bottom-up inventories. Using high-resolution satellite observations, Zhang et al. (2020) estimated a leakage equivalent to 3.7% (~60% higher than the national average leakage rate) of all the gas extracted from the largest oil-producing basin in the United States. Chan et al. (2020) reported eight-year estimates of CH₄ emissions from oil and gas operations in western Canada and found that they were nearly twice that from inventories. Weller et al. (2020) used an advanced mobile leak detection (AMLD) platform combined with GIS information of utility pipelines to estimate CH₄ leakage from pipelines of local distribution systems in the United States. They found that the leakage from those pipelines was approximately five times greater than that reported in inventories compiled based on self-reported utility leakage data.

○ High-resolution inverse model NIES-TM-FLEXPART-variational (NTFVAR)

Inverse modeling is an important and essential method for estimating GHGs emissions. The model uses atmospheric observation data as a controller in atmospheric models to optimize bottom-up emission inventories (prior fluxes).

The NIES-TM-FLEXPART-variational (NTFVAR) global inverse model was developed by Dr.Shamil Maksyutov’s group at NIES. NTFVAR is combined with a joint Eulerian three-dimensional transport model, the National Institute for Environmental Studies Transport Model (NIES-TM) v08.1i, and a Lagrangian model, the FLEXPART model v.8.0. The transport model is driven by JRA-55 meteorological data from JMA. The prior fluxes include gridded anthropogenic emissions from the EDGAR database, such as energy, agriculture, waste and other sectors; wetland emissions estimated by the Wetland emission by the VISIT model; biomass burning emissions estimated by GFAS; and climatological emissions from oceanic, geological, and termite sources. The inverse modeling problem is formulated and solved to find the optimal value of corrections to prior fluxes minimizing mismatches between observations and modelled concentrations. Variational optimization is applied to obtain flux corrections to vary prior uncertainty fields at a resolution of 0.1° × 0.1° with bi-weekly time steps. A variational inversion scheme is combined with the high-resolution variant of the transport model and its adjoint described by Maksyutov et al. (2021).

References:

Chan, E. et al. Eight-Year Estimates of Methane Emissions from Oil and Gas Operations in Western Canada Are Nearly Twice Those Reported in Inventories. Environmental Science & Technology 54, 14899-14909, doi:10.1021/acs.est.0c04117 (2020).

IPCC 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. [Stocker, T. F. Q. et al.]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Maksyutov, S. et al. Technical note: A high-resolution inverse modelling technique for estimating surface CO₂ fluxes based on the NIES-TM – FLEXPART coupled transport model and its adjoint. Atmospheric Chemistry Physics 21, 1245–1266 doi:10.5194/acp-21-1245-2021(2021).

Weller, Z., Hamburg, S. & von Fischer, J. A National Estimate of Methane Leakage from Pipeline Mains in Natural Gas Local Distribution Systems. Environmental Science & Technology 54, 8958-8967, doi:10.1021/acs.est.0c00437 (2020).

Zhang, Y. et al. Quantifying methane emissions from the largest oil-producing basin in the United States from space. Science Advances 6, doi:10.1126/sciadv.aaz5120 (2020).

National Institute for Environmental Studies

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December 22, 2022
The TuFF Age

Newswise — TuFF — Tailored Universal Feedstock for Forming — is a strong, highly aligned, short-fiber composite material that can be made from many fiber and resin combinations. Created at the University of Delaware’s Center for Composite Materials (CCM), it can be stamped into complex shapes, just like sheet metal, and features high-performance and stretchability up to 40%.

Since its introduction, CCM researchers have explored applications for TuFF, from materials for repairing our nation’s pipelines to uses in flying taxis of the future.

Now, armed with $13.5 million in funding from the U.S. Air Force, UD mechanical engineers and co-principal investigators Suresh Advani and Erik Thostenson along with industry collaborators Composites Automation and Maher and Associates are working on ways to improve manufacturing methods for TuFF.

“I am really excited at the opportunity to mature the TuFF pre-pregging process and demonstrate high-throughput composite thermoforming for Air Force relevant components,” said David Simone of the U.S. Air Force.

The goal is to enable lighter-weight composites to become cost-competitive with aluminum for creating small parts found in air vehicles.

Advani explained that when it comes to making aircraft materials more cost-efficient, reducing a material’s weight even a mere kilogram, just 2.2. pounds, will reduce fuel consumption and emissions and can result in thousands of dollars in savings over time.

This is because aircraft are heavy. A Boeing 747, for example, weighs a whopping 404,600 pounds. A B2 Stealth Bomber in the U.S. Air Force, meanwhile, tips the scale at over 43,000 pounds.

“In general, the aerospace industry wants to reduce weight and replace metals,” said Advani, George W. Laird Professor of Mechanical Engineering. TuFF is a good option because the material can achieve properties equivalent to the best continuous fiber composites used in aerospace applications.

Advancing TuFF thermosets

Until now, most of the work around TuFF has focused on thermoplastic composite materials that melt when heated, becoming soft and pliable, which is useful for forming. By contrast, TuFF thermosets have a higher temperature threshold, making them useful for aerospace applications. But TuFF thermosets have manufacturing challenges, too, including the long manufacturing times necessary to make a part.

In this new project, Thostenson and Advani will work on ways to improve the viability of thermoset TuFF composites. To start, the researchers will characterize the starting materials’ mechanical properties to understand how to make TuFF thermosets reliably and consistently. The research team will explore whether they can make the material in a new way, using thin resin films and liquid resins. They will test the limits of how the material forms and behaves under pressure and temperature, too.

“How does it stretch during forming in a mold? What shapes can we make? When does it tear or thin or develop voids that can compromise material integrity?” said Advani.

Having a database for such properties and behaviors will be useful in understanding TuFF material capabilities and limits, and to inform efforts to model and design parts with TuFF.

Thostenson, professor of mechanical engineering, is an expert in structural health monitoring of materials. He will advance ways to embed sensor technology into TuFF thermosets. This would allow the researchers to see from the inside how the material is forming and curing during its manufacture, in hopes of being able to gauge—and improve— the material’s damage tolerance.

It’s intricate work. To give an idea of scale, a single layer of TuFF material is approximately 100 microns thick, about the diameter of the average human hair. The carbon-nanotube sensors Thostenson plans to integrate into the material are smaller still—one billionth the width of a human hair.

“This would allow us to do health monitoring for the materials and parts during service life, but you could also imagine using sensor technology to detect a defect during manufacturing,” said Thostenson.

While it remains to be seen whether this is possible, Thostenson said having this ability could result in real cost savings for manufacturing methods, where real-time knowledge of how a material is curing could help the researchers speed up production. Additionally, if there is a material failure, such as a tear, the sensors could point the researchers where to look in the process.

The research team also plans to develop a virtual modeling system to refine the material-forming process through computer simulation instead of by trial and error. In this way, the team will better understand each step in the material-forming process, enhancing the team’s ability to make TuFF materials consistently and reliably — a must for aerospace applications.

“I am hoping this work will allow us finally to make composites cost competitive with the metal industry,” said Advani.

In addition to Thostenson and Advani, the team includes, from CCM, Jack Gillespie, Dirk Heider, Shridhar Yarlagadda, Thomas Cender, John Tierney and Pavel Simacek, along with four to five graduate students.

University of Delaware

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December 2, 2022